Metered dose medicament inhalers are well known for dispensing medicament to the lungs of a patient. In most cases, the inhalers include a reservoir containing dry powder medicament in bulk form, and means for metering the medicament from the reservoir in discrete amounts for inhalation by a patient.
For example, U.S. Pat. No. 5,503,144, which is assigned to the assignee of the present disclosure shows a breath-actuated dry-powder inhaler having a medicament reservoir. The reservoir contains dry powder medicament in bulk form, and the inhaler includes a metering chamber for removal of the powdered medicament from the reservoir in discrete amounts. The inhaler also includes an air inlet for entraining the removed powdered medicament through a mouthpiece upon patient inhalation. The reservoir and metering chamber of the inhaler shown by U.S. Pat. No. 5,503,144 properly function to dispense discrete amounts of powdered medicament to a patient.
U.S. Pat. No. 6,655,381, which is assigned to the assignee of the present disclosure shows a pre-metered dose assembly for consistently supplying precise doses of medicament for a dry powder inhaler. The assembly includes a cap defining a dry powder delivery passageway and a magazine including a plurality of separate reservoirs for holding pre-metered doses of dry powder. The cap is movable with respect to the magazine for sequentially positioning the reservoirs within the delivery passageway of the cap. A breath-induced low pressure through the dry powder delivery passageway of the assembly entrains dry powder from the reservoir positioned in the passageway for inhalation by a patient using the inhaler. Providing the powdered medicament in pre-metered doses further ensures that the medicament is consistently dispensed to a patient in precise doses.
What is still desired is a new and improved dry powder inhaler for administering dry powder medicament to a patient. The dry powder inhaler will also preferably include a magazine having a plurality of individually separated and sealed, pre-metered doses and mechanisms for advancing the magazine during use and for deploying the doses from the magazine for inhalation by a patient using the inhaler.